There is a design problem in Qt 5.12 (and probably in many other versions) with QWidget methods move(), resize() and setGeometry(). These methods are not virtual, and yet they are redefined at least in subclass QRubberBand, which is a subclass of QWidget.

Redefining an inherited non-virtual method is a no-no - this is well explained for example by Scott Meyers, in Item 36 ("Never redefine an inherited non-virtual function") of his book "Effective C++" (3rd edition).

(I was advised in https://forum.qt.io/topic/122982/serious-design-problem-in-qt-5-12 to report this problem here.)